Some thoughts on the 3 Musketeers bar
The 3 Musketeers bar is just chocolate and nougat. If you want something really tasty, you get the Snickers bar, which has nougat, caramel, and peanuts. If you want something nut-free and still delicious, you can opt for the Milky Way bar, with nougat and caramel. The 3 Musketeers bar seems to appeal to people who like candy, but want to minimize its deliciousness.
Big on Chocolate, Low on Fat
Mars, Incorporated has begun to market the 3 Musketeers bar as a low-fat alternative candy bar, I guess for people who are watching their calories and/or carbs, but still purchasing and consuming candy bars. They do have "45% less fat", presumably compared to something like a Milky Way.
This may be a marketing strategy akin to Subway. In the last decade, Subway has begun to market itself as a healthy, alternative fast food outlet. The poster child for Subway sandwiches was Jared, whose inspirational weight-loss story centered around him walking to Subway twice a day for meals. Jared lost over 200 pounds due to a combination of exercise, a low-fat, sandwich-only diet, and a crippling methamphetmaine addiction. Sure, the sandwiches don't taste all that great, says Subway's parent company, Doctors & Associates, but they're much healthier.
However, Subway still keeps a big rack of chips right next to every counter. There is a discount on chips and soda with purchase of a sandwich. And the "low-fat" menu items become much more "high-fat" if you add the freely available mayonnaise or olive oil to your sandwich. It still isn't healthy by any means; it's just less unhealthy than a place like McDonald's. One almost wonders if Subway is intentionally attempting to lure in the obese, people who might identify with the "Before" Jared, only to eventually give in to the temptation of the Value Meal. People who overeat would seem to be a golden demographic for a restaurant chain.
Gateway bars
By the same reasoning, the 3 Musketeers might be considered a gateway bar. If the weight-watcher who buys 3 Musketeers as a less-tasty, less-unhealthy snack has a slip, he will hopefully binge on 3 Musketeers, rather than some other brand. Even while a healthy, Musketeer-heavy diet lasts, the dieter still has to get that selection from the candy aisle. Once he's there, there's little to stop him from getting a "harder" candy bar, like a Snickers, or even a Butterfinger.
Butterfinger is the candy aisle equivalent of heroin: its filling is sugar and peanut butter blended together in its most concentrated form, without any nougat to provide a protective layer of blandness. The Velvet Underground had an unreleased song where Lou Reed sang, "Honeycombed peanut butter center, it's my life, it's my wife." Even the official Butterfinger web site says that buying the largest possible Butterfinger bar to share with a date is a surefire "deal-sealer", whatever sort of honeycombing that is supposed to imply.
Urban Legend
Someone told me a story about the origin of the names of Milky Way and 3 Musketeers bars. The legend goes that Milky Way and 3 Musketeers were released on the same day, but the labels were accidentally switched. This has a strain of plausibility, because a Milky Way bar has three ingredients (to review: chocolate coating, nougat, caramel), and it is easy to envision the smooth chocolate nougat interior of the 3 Musketeers bar as a veritable galaxy of mediocre taste.
So, the labels were switched, and both bars were so popular, the candy company couldn't very well reverse themselves and change the names back after they were such a hit. And that is the Just So Story of why 3 Musketeers has only two damn ingredients.
However, Milky Way came out in 1923. 3 Musketeers wasn't released until 1932. Originally, it had three different pieces and three different flavors: vanilla, strawberry, and chocolate. This legend is just not true, though people in Mauritania might believe it.
Little differences
In England, our 3 Musketeers is known as a Milky Way. Our Milky Way is England's Mars bar. The American Mars bar no longer exists. Because of the metric system.
Digression
My lovely roommate bought large candy bars for the trick-or-treaters, only some of which were later confiscated by the author. Most kids demonstrated the proper awe for the too-much-fun sized candies, and the impressive selection, except for one bold young boy, dressed as a Power Ranger. (Kids still watch Power Rangers? That show is still on? I need to check in with Mom about this one.) The young Green Ranger reached in and snatched two full-sized Snickers at once. I was horrified by his greed, but quite impressed by his moxie, as the candy bars barely fit through the top of his plastic pumpkin pail.
Now, would he have demonstrated such courage for two full-sized 3 Musketeers bars? I sort of doubt it.
Fun Facts
My tireless Internet research has failed to discover when 3 Musketeers changed to their current flavor configuration. However, the FAQ on the official 3 Musketeers site yields some fascinating information.
The chocolate nougat (mostly egg whites and sugar – sorry, vegan friends) is covered in chocolate by a process called "enrobing" (in a facility that also manufactures peanut products – sorry, Matt). Enrobing involves "a continuous curtain of liquid chocolate" and also "a rotating chocolate covered wheel". Awesome.
Actually, since it's milk chocolate, the nougat didn't really make or break the candy's veganosity.
Spokesmen
After the runaway success of both the Count of Mighty Crispy bar, and Queen Marshmallots, candymakers scrambled to adapt another of Alexandre Dumas pere's adventure novels into a confectionary treat. They ended up choosing the Musketeers.
D'Artagnan represents the candy bar, though he's not one of the titular Musketeers. He stepped in when Aramis got the boot from Mars, Incorporated. Maybe it's because Aramis became a priest, and he's not a worldly, nougat-hungry gentleman like the others. After all, the 3 Musketeers® Brand Athos is "brilliant and brave but also clumsy like a nutty professor" and "a scatterbrained hero with a heart of gold." 3 Musketeers® Brand D'Artagnan is "always the first to charge into a fray". He's "courageous, gallant and always wins the day". Meanwhile, 3 Musketeers® Brand Porthos is "James Bond with a saber".
I like to think of D'Artagnan as sugar, Athos as milk chocolate, and Porthos as blended egg whites. Blended egg whites with a saber.